Pneumatic delivery plant for raising liquids from great depths



May 29, 1934. o. MEYER PNEUMATIC DELIVERY PLANT FOR RAISING LIQUIDS FROMGREAT DEPTHS Filed NOV. 29, 1932 Patented May 29, 1934 PATENT QFFHEPNEUMATIG DELIVERY PLANT FOR RAISING LIQUIDS FROM GREAT DEPTHS OttoMeyer, Nuremberg, Germany, assignor to firm Armaturenund Maschinenfabrikflirt.- Ges., Vorm. J. A. Illilpert, Nuremberg, Germany ApplicationNovember 29, 1932, Serial No. 644,899 In Germany December 1, 1931 1Claim.

Liquid pressure installations with bells arranged in stages and providedwith automatically controlled shut-off members are known, in which thedelivery of the liquid is effected by periodical changes of pressure.These installations fail when it is a question of delivering liquids ofvarying viscosity, particularly viscous liquids, such as petroleum,water containing gas, lyes and the like, from very great depths, sincein delivering from very great depths diiferences of temperature occur inthe individual bells, as a result of which, in delivering from one stageto the next, owing to the different frictional losses that occur in thedelivery pipe, manometric delivery heads of different magnitudes occur.

In the case of the great depths that come into consideration moreparticularly in delivering petroleum, amounting to 800 metres or more,the liquid to be raised has a considerably higher temperature at thebottom than it has when discharged at the ground level, and theviscosity of the oil to be delivered is also influenced by its greateror smaller percentage of gas, which may also be influenced by itstransfer to the successive delivery bells. Even at a depth of 100 metresit is already necessary to take into consideration that the temperatureof the oil to be delivered is about 40 C. at the point where it is takenin, whereas at the point of delivery above ground it has fallen tobetween 20 and 30 C. Furthermore the viscosity of the oil is alsoappreciably influenced by the removal of gas therefrom when the oil isbeing pumped from one delivery bell into the one above it.

Owing to these losses of heat and gas the viscosity of the crude oilincreases, so that very different pressures are necessary for deliveringit into the successive delivery bells. Owing to this the bells are notall filled in the same length of time, but the lower bells, inconsequence of the smaller frictional losses in the pressure pipe, arefilled considerably more quickly than the upper bells. As a result ofthis, the continuous delivery of the plant is endangered, unless thediffering viscosity of the oil occasioned by the change of temperatureand by the withdrawal of gas from the oil is allowed for.

These fluctuations in viscosity, and the differences of pressureoccasioned thereby, do not admit of being satisfactorily dealt with bycalculation, since the viscosity of the oil is also afiected bysubsidiary phenomena, which cannot be supervised, for instance at thecommencement of the delivery the conditions are quite different fromwhat they are when the plant has been in operation for a long time, asthe temperatures gradually tend to become equalized. Furthermore it hasalready been mentioned that the alteration in the viscosity is alsodependent upon the losses of gas. It is not possible to design theindividual delivery bells at definite distances apart determined on thebasis of these phenomena, for other delivery conditions also arise, asalready explained.

The regulating oi the fluctuations of viscosity that occur by theinsertion of valves, controlling members, or floats in the bellsarranged at great depths is practically impossible, particularly when itis borne in mind that in the petroleum there are serious impurities,particularly sand, which precludes the reliable working of suchsensitive members, specially as the well bores driven to great depthsare only of very small diameter, and thus the controlling members couldonly be given small dimensions. Such solutions would be impracticablesince the use of the controlling members in installations of very greatdepths is very costly, requires time, and interrupts the continuousoperation, which is desirable for the delivery of mineral oil. Since forall the parts located below ground the highest requirements as regardsreliability and durability have to be made, the problem of providing forsatisfactory and reliable working of the superposed bells, and ofallowing for the arbitrary differences of viscosity of the oil to bedelivered and of the diilerent delivery pressure heads that adjustthemselves, must be solved in some fundamentally diiierent manner.

According to this invention the lowest bell is made considerably largerthan those above it, and all the delivery bells, with the exception ofthe two lowest, are connected with their delivery pressure pipes by anelevated connecting pipe in each instance, acting as apressure-compensating pipe.

The output of the plant as a whole is determined by the quantity of oilentering the lowest bell in a length of time fixed by positively actingcontrolling means. Owing to the varying per 100 centage of gas in theoil, and owing to the varying position of the underground oil surfacelevel outside the well, it is not possible always to admit the samequantity of oil into the bell in the predetermined constant unit oftime. For this '05 reason the volume of the lowest bell is increased. toact as an accumulator or storage space. From this bell the same quantityof oil is then always delivered. Since in a unit of time unequalquantities flow in, it follows that by the enlarging D of the bell thesame quantity of oil can constantly be taken out of the bell.

One example of construction of the delivery plant according to theinvention is illustrated in longitudinal section in the accompanyingdrawmg.

The lowest bell 1 fitted into the bore pipe is of considerably greatercapacity than the bells 2, 3 or 4. The bell 2 is made somewhat largerthan the bells 3 and 4, which are equal to one another in size. Thedelivery bells 1 and 3 are connected to an air pipe 5, which passesthrough the bells 2 and 4 without communicating with them. The bells 2and 4 are connected to an air pipe 6, which traverses the bell 3. Thedelivery bells are connected with one another by delivery pipes 7, 8, 9and 10, which are closed by ball valves 11, 12 or the like. In order tocompensate for the oscilating masses of air, there is arranged in thepipe 6, which is the shorter one of the two air pipes, at compensatingreservoir 13, the volume of which corresponds to the diiference involume between the two pipes 5 and 6. The bells 3 and 4 are connected topipes 14 and 15 extending upwards therefrom and communicating with theair pipes 5 and 6 respectively at points a considerable distance abovethe bells with which they are connected, as indicated in the drawing,where the pipe 14 reaches nearly up to the surface of the ground and thepipe 15 reaches nearly up to the bottom of the bell 4. The length of thepipes 14 and 15 is determined by the spacing of the bells.

The method of operation of the plant is as follows:-

After the bell 1 has become full the pipe 5 of the bells 1 and 3 issupplied with compressed air. The bell 1, in consequence of the smallerviscosity of the oil, will begin to empty itself sooner than the bell 3,in which, in consequence of the higher viscosity of the oil, a higherpressure is required than in the bell l, and the oil will flow to thebell 2, and, because the volumeof the cell 1 is greater than that of thebell 2, will also fill part of the air pipe 6. With this filling of theair pipe 6 of the bell 2, however, the pressure also rises in the airpipe 5 of the bells 1 and 3, and it continues to rise, until thepressure required for delivering the liquid from the bell 3 to the bell4 is reached, after which the emptying of the bell 3 into the bell 4commences.

When the compressed air, after the reversal, acts through the air pipe 6upon the bells 2 and 4, the oil in the air pipe 6 will beforced backinto the bell 2, and part of the oil in the bell 2 will ascend, afterfilling the bell 3, into the connecting air pipe 15 of the hell 3,because the volume of oil that had been contained in the bell 2,together with the volume of oil that had previously been forced up intothe pipe 6, cannot be accommodated by the bell 3 alone. Owing to theascent of the oil into the pipe 15 a rise of pressure takes place in thepipe 6, and also acts through the elevated connecting air pipe 14 uponthe bell 4, so that in the latter the pressure rises, and it can emptyitself above the surface of the ground.

It will be understood that if the pipes 5 and 6 were directly connectedto the tops of the bells 3 and 4 in the usual manner, without theinterposition of the pressure-compensating pipes 15 and 14 respectively,then when the surface level of the oil in the bell 3 for instancereached the point of connection between this bell and the pipe 5, anycontinuance of the air pressure applied to the bell 2 through the pipe 6would simply cause the oil to leak out of the hell 3 and flow down thesupply pipe 5 into the bell 1, thereby wasting the work already done inraising it, besides preventing any rise of pressure in the pipe 6.

The elevated connecting pipes 15 and 14, which serves as compensatingpipes for the different delivery pressures that prevail between theindividual bells, will accordingly compensate quite automatically forthose irregular changes of viscosity which might produce disturbances inthe pumping operation.

The compressed delivery air becomes enriched with mineral oil gases inthe course of operation. This enrichment may continue to such an extentas to produce an explosive mixture of air and gas, containing from 6 to7 per cent. of mineral oil gas. In order to obviate this risk, insteadof operating the apparatus with air, it is operated with a mixture ofair and gas containing from 50 to 60 per cent. of mineral oil gas, whichis obtained directly from the bore hole.

What I claim is:-

Delivery plant operated by compressed air or gases for raising liquids,particularly mineral oil, from great depths, comprising a series ofsuperposed delivery bells, the lowest delivery bell being considerablylarger than any of the others, liquid delivery pipes connecting thesuccessive bells with one another, a pipe for supplying gaseous fluidunder pressure to the lowest delivery bell and to the alternate deliverybells above it, a shorter pipe for supplying gaseous fluid underpressure to the lowest delivery bell but one and to the alternatedelivery bells above it, a compensating reservoir communicating with theshorter supply pipe, the volume of the compensating reservoircorresponding to the diiference in volume between the two supply pipes,elevated pressure-compensating pipes connecting all the bells except thetwo lowest individually to the supply pipes, and means for producingperiodical changes of pressure in the delivery bells through the mediumof the supply pipes.

OTTO MEYER.

